Ferrell 06Z pressure 1981 - 987.6 989.8 991.9 984.8 978.6 987.2 995.2 988.5 981.1 976.8 978.5 1982 989.6 986.5 978.1 980.2 986.5 980.3 989.3 975.1 977.0 980.1 984.1 994.4 1983 991.8 994.5 984.9 979.7 985.5 988.8 981.6 - - - - - 1984 993.6 989.1 979.0 979.9 987.2 980.5 975.5 985.7 981.0 - - - 1985 - 988.6 987.0 - 989.4 - 975.4 985.9 976.2 977.3 - - 1986 - 993.3 992.2 981.4 992.1 991.8 981.1 984.4 979.6 974.0 976.0 981.5 1987 - 988.8 987.6 989.7 984.2 988.5 993.8 976.7 989.4 980.4 979.2 985.9 1988 988.4 985.2 986.5 984.6 990.9 995.9 - 976.5 985.2 990.4 980.9 982.4 1989 984.5 985.6 984.8 989.6 - - 980.9 - - 976.6 975.6 988.6 1990 988.3 982.9 987.0 993.1 999.7 989.6 999.0 982.4 974.7 982.9 984.3 984.5 1991 983.4 989.7 983.4 988.4 989.0 992.6 - - - - 984.6 995.1 1992 988.8 997.4 988.3 987.3 993.3 996.6 985.1 - - - - - 1993 - 977.8 985.6 981.7 982.9 975.8 972.3 978.5 976.6 976.1 979.1 982.4 1994 983.6 982.5 978.5 985.4 984.9 999.0 989.2 975.0 989.4 977.8 983.9 980.1 1995 980.1 981.3 990.7 983.5 981.1 988.3 1001.5 986.4 978.1 979.7 977.4 977.1 1996 985.3 990.1 985.1 978.8 985.7 982.6 982.0 987.5 989.2 972.2 986.9 984.9 1997 988.3 989.5 980.0 986.0 973.4 987.2 979.7 977.9 981.2 976.9 986.7 990.2 1998 985.3 980.6 982.0 976.3 983.0 977.0 980.6 - - - - - 1999 - 987.2 - - - - - - - - - - 2000 - - - - - - - - - - - - 2001 - 988.0 985.3 979.6 985.3 982.3 987.1 983.6 979.3 972.3 975.8 976.2 2002 983.1 977.9 990.0 981.2 991.9 995.0 989.3 979.1 986.7 989.7 983.7 978.6 2003 - - - - - - - - - - - - 2004 - - - - - - - - - - - - 2005 - - - - - - - - - - - - 2006 - - - - - - - - - - 978.5 982.9 2007 986.2 983.0 989.8 984.8 986.8 985.7 996.7 979.1 977.9 982.4 981.4 975.6 2008 979.8 979.7 984.8 985.7 983.8 977.0 980.1 982.6 972.3 973.7 - - 2009 - - - - - - - - - - - -